James e



(No Model.)

J. E. WOODBRIDGE.

SCREW CUTTING DIE.

No. 399,367. Patented Mar. 12, 1889.

Wzessw Unirse STATES yParam Orrtcno JAMES E. YOODBRlDGE, OF HARTFORD, CONNECTICUT, ASSIGNOR TO Tl [E PRATT & \\vll'l'l`.\"'l\Y COMPANY, OF SAME PLACE.

SCREW-CUTTING DIE.

SPECFICATION forming part of Letters Patent No. 399,367', dated March l2, 1889.

Application filed October 5, 1888. Serial No. 287,343. (No model.)

To all who/:t if '1m/U concern:

l@ it known that l, Janes E. boulimia-in,

a citizen ol the lfnited States, residing at llartford, in the county of llartt'ord and State of Connecticut, have invented certain new and useful Improvements in Screw-Cutting Dies, of which the following is a specification.

This invention relates to that class of screweutting dies having renewable chasers, and has for its object to furnish. an improved die of that class in which the chasers ale adjustable by means of the improvements and combinations hereinafter more fully set forth.

In the drawings accompanying and forming a part of this specification, Figure l is a front view of a die` embodying my im1noveinents. l `ig. i is a sectional side elevation ol.' the same. Fig. il is a side elevation, in which dotted lines ment may be elliecter'l bythe means hereinafter described. f

The dic-body rearward ol` slots S has a screw-thread, T, onto which the annular collet N is fitted by a corresponding thread. This collet or ring N is or may be furnished with holes (l, or similar means, whereby a wrench or'othcr suitable tool may be used for adjusting it on said thread T. The inner and forward part of said ring has formed therein two beari11g-surfaces, one conical and one cylindrical. The cylindrical surface 2O is at the extreme forward part of the ring, and has a show some features ot the interior eonstruction. Fig. -t is a sect-ion in line CL c, Fig. l. Fig. 5 shows one of the chasers in four views, which are drawn in projection, one view with the other, in the usual manner.

Similar characters designate like parts in all the figures.

The body of the die which carries the series of chasers is designated by B. This part B is usually bored, as shown, to permit the passage through it of the bolt or other piece being threaded. The front end of said die-body (at left hand in Figs. 2 and 3) has a series of radially-disposed slots formed to receive the L chasers, one of which slots is designated by S i in Figs. 2 and Into these slots the chasers C, two or more in number, are respectively fitted closely, but not firmly. each have a beveled (or concave) groove, 3,

The chasers whereby they are held in place in said slots S by means of pointed screws t, whose points 5 bear in said grooves. tained in tapped holes suitably located, substantially as shown, in the die-body, said screw-points being located and constructed to bear against the rear side of said groove,

tom of the slot S, as shown at (j, Fig. t

threads, S, and on their outer ends are bev- Screws t are con thereby forcing the chasers back onto the bote flhe chasers have the usual cutting teeth or eled at a suitable angleas,for instance, the i 'angle X, Fig. 5whereby the chaser-adjusti close-working lit on the cylindrical forward end, 22, of the collet or die-laid)- B. ly this means any strains acting on said rimz crosswisc to the axis ot' the die are resisted by the said surface 20, and the accurate position on the die-body of said ring is obtained by a close cylindrical bearing which is readily made accurately, and is not obtained by the aforesaid engaging screw-threads, which are more dillicult and expensive to make and much less reliable for t-he said purpose, for in practice it is desirable the threaded part- T should be freely fitted, while such mode of iitting renders the same incapable of accurately and firmly holding the ring in place. Between the cylindrical bearing 2O and the internal thread, 19, there is the internal conical bearing-surface, l0, formed smallest at the front end, where it joins (or comes contiguous to) the cylindrical surface 20. Against this conical surface the chasers C take their bearing, as well shown in Fig. 1, and by screwing the ring N a greater or less distance onto the diebody B the chasers may be adjusted within given limits to cut screws to any required gage.

For holding or setting the collet N in place, I euta slot, li, entirely through the same and in the threaded part thereof, crosswise to the axis of the thread. A binding-screw, l5, ex-

tending across said slot, serves to spring the thin part 16, and thereby bind and securely 9 clamp said ring from turning on the die-body.

The operation of cutting a thread is carried out in the usual manner and forces the chasers firmly outward againstthe ring N, and owing tothe incline described also tends to IOO keep them against the bottoni of the chaserreceiving slots.

Having thus described my invention, l claiml. The coinbiiiation, in a screw-cutting die, with the die-body formed cylindrical at its forward end and having therein radially-disposed chaser-receiving slots and having a screwthread rearward of said slots, of chasers contained in said slots, and an annular ring having an internal thread tting the thread on said die-body, having a cylindrical bearing fitting the cylindrical forward end of said die-body, and having a conical portion between said cylindricaland threaded portions for taking the outward thrust of the chasers, all substantially as described.

f2. The co1nbination,in a screw-cutting die,

with the die-body B, having the cylindrical forward part, 22, the thread T, and carrying' the chasers C in the radial slot-s S, of the chaseradj nstin g ring N, threaded to engage with the thread -T, and having the inclined surface l0,

for receiving the thrust of the chasers, and' the cylindrical surface 20, bearing on said surface 29, substantially as described, and for the purpose specified.

3. The combination,in a screw-cutting die, of the threaded die-body and the Chaser-adjusting ring having the slot 14, and a binding- 3o 

